Window Inserts

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DuaeGuttae

Minister of Fire
Oct 26, 2016
1,621
Virginia
A couple of weeks ago in a woodstove thread, member @ctyankee suggested window inserts for someone dealing with single pane glass windows. @begreen asked about the transparency of the vinyl. My husband and I were just talking about our inserts this morning (as we were having 22 degree temperatures outside), and I thought it might be good to put a thread in the Green Room for reference if they come up again on the forum..

My family lives in a house in south central Texas with double-paned windows with aluminum frames. Some have leaks, but our energy auditors recommended fixing the leaks but keeping the windows because the cost of replacement would be astronomical, and they weren’t too bad. A couple of years ago, we installed window inserts in all the windows that we could, and we have really appreciated the benefits. Our inserts have aluminum frames and are from windowinserts.com . I believe that there are fancier vinyl framed inserts that can be made curved available from indowwindows or something like that.

The inserts are noticeable, and I think would be strange in beautiful wooden windows in a traditional setting. Our home is a more modern stucco and with the existing aluminum frames, they’re not that noticeable.

Our master bedroom is on the second story of our house and has a wall of windows that face west. There is some shading from trees, but the windows turn the place into an oven. We have cellular blinds that we leave closed pretty much all summer and in really cold days and nights in the winter. In this room the existing blinds are in between the glass window and the window insert, and that setup really helps cut down on heat transfer.
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This second photo comes from the north side of our house. The night before last we had freezing rain move in from the north, and the windows were completely glazed in the morning. These windows do get some sun in the morning because it’s not straight north, but it has been cloudy here and well below freezing. Nevertheless, we think it is a testament to the window insert that the ice has not yet melted from our interior heat because of the window insert and air gap.

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We leave our inserts in year round because we need protection from both heat and cold. In our particular case we are unable to open windows during the nice weather down here because those times correspond with our worst allergy seasons. That would be a drawback to having inserts.

We made upgrades to our house in other areas (sealing around outlets and light switches, getting better sealed LED in existing recessed light fixtures, putting radiant barrier on a south facing wall in our attic space) as that same time we installed window inserts so I can’t say exactly what these inserts have done to our bills, but the changes we made lowered our electricity usage by about one third. (Some of that may also be due to relying on inverter window A/C rather than central air when we can.) I can say, however, that they have really helped make our experience of our living space much more comfortable.

Yesterday I was noticing that an exterior door we never use and that gives us trouble was once again leaking where I had put new weatherstripping in a couple of years ago. I used thumbtacks and covered it over with some extra radiant barrier we have which helped, but I was wishing I had a window insert to pop in there. We won’t go that route, but it tells me something about how much I appreciate these things.

I thought it might be helpful to start this thread for future reference. @ctyankee or anyone else who has input or questions, feel free to contribute. There may be better options out there, but this one has been a help to us in our circumstances.
 
Thanks for the writeup. They can look OK in traditional wooden windows, but it helps that I happen to have white as a main color in this room. I only use them for the heating season.

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When I lived in Houston I had single payne windows on my house that let in so much heat/sun that those bedrooms couldn't be used. I wish I knew about the interior window frames. I was young, lol. I ended up planting the largest crape myrtles I could find infront of the windows and this worked well.

I drove by the house probably 10 years after I sold it. The new owners had taken down the crape myrtles and installed a black window screen of sorts. It must reflect the heat back out or stop the sun from heating the room. Since then interior shades that insulate have become available too, but I probably couldn't have afforded them at the time. I was so house poor I don't know how I ate.
 
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Thanks for the writeup. They can look OK in traditional wooden windows, but it helps that I happen to have white as a main color in this room. I only use them for the heating season.
Thanks for posting that picture. You’re right that the white works just fine there. Our windows are beige as are our inside walls and outside walls. It was nice that they had almost an exact match for our color.
 
When I lived in Houston I had single payne windows on my house that let in so much heat/sun that those bedrooms couldn't be used. I wish I knew about the interior window frames. I was young, lol. I ended up planting the largest crape myrtles I could find infront of the windows and this worked well.

I drove by the house probably 10 years after I sold it. The new owners had taken down the crape myrtles and installed a black window screen of sorts. It must reflect the heat back out or stop the sun from heating the room. Since then interior shades that insulate have become available too, but I probably couldn't have afforded them at the time. I was so house poor I don't know how I ate.

Our energy auditors recommended as a(n expensive) possibility solar shades on the exterior of the windows. Our neighbors have some, and they do work well. The problem that they’ve had, though, is that we live in a very windy area, and theirs get damaged if they aren’t retracted. I’ve thought about trying to tack up some of our garden shade cloth just as an experiment. It’s just hard to “tack” anything to our exterior stucco temporarily.
 
Greenhouse shade cloth is quite remarkable at knocking down the heat. We found this out last summer during the 100º heatwave. I would think that stretching it across some permanently mounted triangular frames would work well. The wind should blow through it rather than lift it off as long as it is securely clamped on both ends.
 
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i have replaced 3 full homes worth of inserts over the last 25 years 2 of those were traditional double hungs, the last were swing outs ( can't remember the proper name). the first two I used wood framed inserts- the last was alum. framed ( replaced failed Pella units which themselves were alum so it was a match). So here is the scoop if you have wood framed windows then the best type to use are woodframed or Fiberglassed framed- expansion contraction between these two are almost identical and match that of your wood framed home. The expansion contraction of vinyl is similar also but the dang things shrink with age ( The sellers don't tell you this and it shows up a couple years down the road) which puts you back at sq. one. Alum . expansion and contraction is a lot more than wood and again leads to leaks. Another thing about Alum. is the convection of heat cold through the framing. all of these were double pane units with just dead air space between ( gas charged units always leak the gas out after a few years- you will know when it happens as the windows will fog up in between the panes or the panes will contact each other in the middle and then you get big oval ice sheets on the interior side of your windows - the term used in this case is collapsed pane syndrome). In all 3 cases the reduction of heating and cooling costs were significant. the last home, due to the collapsed panes , was apx 70% savings . Due to budget constraints i did not use the 3 pane units ( would have liked to though). I did not use replacement inserts from Pella ( way over priced).